反应详情

p-Toluenesulfonic acid (0.8 g) was added to a suspension of Compound 45a (1.0 g) obtained in Step A of Example 45 in toluene (27 ml), followed by heating under reflux for 30 minutes. After being allowed to stand for cooling, a saturated aqueous solution of sodium bicarbonate was added to the reaction solution for neutralization, followed by extraction with ether. The organic layer was washed with a saturated saline and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The resultant residue was purified by silica gel column chromatography (chloroform/methanol=20/1) to give Compound 67 (0.59 g, 62.2%) as yellow crystals.

1. temperatureby heating
2. temperatureunder reflux for 30 minutes
3. temperaturefor cooling
4. extractionfollowed by extraction with ether
5. washThe organic layer was washed with a saturated saline
6. dry with materialdried over anhydrous magnesium sulfate
7. distillationthe solvent was distilled off under reduced pressure
8. customThe resultant residue was purified by silica gel column chromatography (chloroform/methanol=20/1)